A side curtain air bag is typically stored inside a vehicle headliner. At the onset of a side collision or a vehicle rollover, the curtain air bag is deployed and inflated along the side of the vehicle, to protect the vehicle occupant's head and upper torso against impact with the side of the vehicle.
A known way of constructing a side curtain air bag is to provide a pair of panels that are sewn together to form an inflatable cushion. Alternatively, rather than using a pair of panels a main panel that is folded over a centerline is used to provide the panel or panel parts that are sewn together to realize the inflatable cushion. The manner in which the panels are sewn together configures the inflatable cushion into inflatable compartments that are inflated to protect the occupant's head and upper torso during a side impact or a vehicle rollover. It is also known to inflate the inflatable compartments by a cylindrical passage located in the inflatable cushion, and which distributes inflation fluid (e.g. inflation gas) from a source along the length of the cushion and into the inflatable compartments of the cushion.